Introduction: Fail: a Full Tilting 3-wheeled Cargo Bike

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after building some "standard" cargo bikes i decided to get my hands dirty again, this time with something very special. i wanted to build an ideal cargo bike combining the stability of a three-wheeler (e.g. https://www.instructables.com/id/how-to-build-a-cargo-bike/ ) with the possibility to take curves like being on two wheels (e.g. https://www.instructables.com/id/build-a-2-wheel-cargo-bike/ ).
long story short: in the end i managed to build a bike that has the above features, but has simply become too heavy to load anything on it. plus steering is something you really have to learn with this monster:

surely it would be possible to improve this construction massively, but i think this would exceed my possibilities in regards of time and money.
BUT if some builders out there want to try their luck, here is what i learned so far and how i built this machine.

Step 1: Research

the first step was to do extensive research. since i am not an engineer it took me quite some time to understand the concepts behind it. an incredible source of technical inspiration was the tilting group over at yahoo: http://autos.groups.yahoo.com/group/tilting/ although primarily concerned with tilting concepts in regards to engine driven constructions the group is surely the best place to find information about constructing a tilter.

also very inspiring are tilting tricycle constructions built before:
- the jetrike: http://www.jetrike.com
- onya cycles' front-end loader. unfortunately the website (http://onyacycles.com) seems to be dead, but here are a some impressions: http://tinyurl.com/as2cc5m
- youtube has quite some videos about tilting trikes: http://tinyurl.com/ajkp98w

Step 2: An Early Prototype

after researching and sketching a few ideas i decided to grab some parts i had lying around and started with a very simple prototype. what i learned was that building such a vehicle needs a high degree of accuracy, which was ot the case with the prototype. the consequece was that the steering mechnism locked itself every now and then.

Step 3: Building the Trike: Lean-steer Part

after building the prototype i went back to my drawing desk and made a few more sketches. this led to an improved version of the steering/tilting mechanism. back in the workshop i started building the trike.

the first part to build was the lean/steer mechanism. as you can see in the first photo the core part are ball heads which allow a tilt of 30° (2x15°) and, at the same time, the turning of the wheel axles. in the second image you can see how it tilts.

Step 4: The Frame

building the frame was quite straightforward. as usual i cannibalized an old bike for the rear triangle and then added the front part.

Step 5: First Test Assembly

after adding the frame for the cargo basket i assembled it for the first time.

Step 6: Steering

now came the hard part: constructing the steering mechanism. i started with the usual steering design used with 2 wheel cargo bikes (see: https://www.instructables.com/id/build-a-2-wheel-cargo-bike/#step4 ) but it took me quite some time to figure out how to transmit the steering force adequately to both wheels without allowing the whole thing to lock itself in any angle. i don't want to go too much into detail here but i hope the principle is visible in the photo.

Step 7: That's It!

as said in the introduction the whole thing is
- too heavy
- the wheels are way too far in the front and
- steering is a pain in the a**

the project took quite some time and i also spent a little bit too much money for my taste, but i'm sure i can use the knowledge i gained in the one or the other way.